title: Expression of P2X4R mRNA and protein in rats with hypobaric hypoxia-induced pulmonary hypertension.
abstract: BACKGROUND
  The experimental pulmonary hypertension that develops in hypobaric hypoxia is characterized by structural remodeling of the heart. The P2X4 receptor (P2X4R) controls vascular tone and vessel remodeling in several blood vessels, and it has emerged as a key factor in the enhancement of cardiovascular performance.
  
  
  RESULTS
  To study the possible effects of hypobaric hypoxia on the P2X4R-synthesis system, 150 male Wistar rats were housed in a chamber at the equivalent of the 5,500 m altitude level for 21 days. After 14 days' exposure to hypobaric hypoxia, pulmonary arterial pressure (PAP) was significantly increased. In the right ventricle (RV) of the heart, P2X4R expression was significantly increased on days 1 and 14 (mRNA) and on days 7 and 21 (protein) of hypobaric hypoxic exposure. Immunohistochemical staining for P2X4R protein became more intense in RV in the late phase of exposure. These changes in P2X4R synthesis in RV occurred alongside the increase in PAP. In addition, P2X1R and P2Y2R mRNA levels in the RV were significantly increased on days 1, 14, and 21, and day 5, respectively, of exposure. The level of P2X1R protein in the RV was significantly increased on day 21 of exposure.
  
  
  CONCLUSIONS
  Conceivably, P2 receptors, including P2X4R and P2X1R, might play roles in modulating the RV hypertrophy that occurs due to pulmonary hypertension in hypobaric hypoxia.
authors.affiliation: Department of Pathology and Laboratory Medicine, National Defense Medical College, Tokorozawa, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Ohata
authors.forename: Sho
authors.initials: S
authors.lastname: Ogata
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Fumiko
authors.initials: F
authors.lastname: Kanazawa
authors.forename: Maki
authors.initials: M
authors.lastname: Uenoyama
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Hiroi
authors.forename: Susumu
authors.initials: S
authors.lastname: Tominaga
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kawai
mesh_terms: D000532:Altitude Sickness / Q000150:complications / Q000378:metabolism / Q000473:pathology; D000818:Animals; D005786:Gene Expression Regulation; D006352:Heart Ventricles / Q000378:metabolism* / Q000473:pathology; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D017380:Hypertrophy, Right Ventricular / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D000860:Hypoxia / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008297:Male; D009124:Muscle Proteins / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D058474:Receptors, Purinergic P2X1 / Q000096:biosynthesis; D058848:Receptors, Purinergic P2X4 / Q000096:biosynthesis*; D058473:Receptors, Purinergic P2Y2 / Q000096:biosynthesis; D013997:Time Factors
chemical_list: D009124:Muscle Proteins; D012333:RNA, Messenger; D058474:Receptors, Purinergic P2X1; D058848:Receptors, Purinergic P2X4; D058473:Receptors, Purinergic P2Y2